But a fair-minded person would have to acknowledge that the N.L.R.B.’s action is exactly the kind of overreach that should embarrass Democrats who claim to care about job creation. It’s paralyzing, is what it is.

The law, to be sure, forbids a company from retaliating against a union. But the word “retaliation” suggests direct payback — a company shutting down a factory after a strike, for instance. Boeing did nothing like that. It not only hasn’t laid off a single worker in Washington State, it has added around 3,000 new ones. Seven out of every 10 Dreamliners will be assembled in Puget Sound.

Before expanding to South Carolina, Boeing asked the union for a moratorium on strikes — precisely because it needed to get the airplane into the hands of impatient customers. The union said it would agree only if Boeing promised never to manufacture anywhere but Puget Sound. Boeing refused — as any company would.

It is a mind-boggling stretch to describe Boeing’s strategy as “retaliation.” Companies have often moved to right-to-work states to avoid strikes; it is part of the calculus every big manufacturer makes. The South Carolina facility is a hedge against the possibility that Boeing’s union work force will shut down production of the Dreamliner. And it’s a perfectly legitimate hedge, at least under the rules that the business thought it was operating under.

That is what is so jarring about this case — and not just for Boeing. Without any warning, the rules have changed. Uncertainty has replaced certainty. Other companies have to start wondering what other rules could soon change. It becomes a reason to hold back on hiring.